The Djamaa El Djazair mosque is being built facing the picturesque bay of Algiers as part of a complex that will include a one-million book library, a Quranic school and a museum of Islamic art and history.

It will also have a 265-metre high minaret (874 feet) - the world's tallest - as well as a 20,000 square metres prayer hall capable of accommodating up to 120,000 worshippers. The complex will be located between a future tourist hotspot and working class districts that were once a bastion for extremists. The North African country was battered by a civil war in the 1990s between the government and insurgents that killed some 200,000 people. More than two decades later, armed groups remain active in parts of Algeria and the country has been hit by several devastating attacks claimed by Al-Qaeda in recent years.

"Some have accused us of building a temple for the extremists," said Ahmed Madani, an adviser to the minister of housing responsible for the construction, which is being carried out by a Chinese firm.

"On the contrary, it will be a heavy blow for the extremists. They are the ones hostile to this project," said Madani.

The new mosque - due to be completed in 2017 - will be "an emblem of moderate Islam in Algeria and a shield against all forms of extremism," said Madani, who hopes it will draw Muslims away from terrorist-run houses of worship.